Skinny Bala Shark

Question
I have a 55 gal tank with a dragon fish, 2 clown loaches, 1 Plecostomus, and 2 Balas.  The Balas were the same size at first and now one appears to be considerably smaller. He looks very skinny.  I watch to make sure that he is eating and he is.  He actually has a ridge on his top  by his dorsal fin where he appears to be getting sunken in. All the fish in the tank are about 3 years old and all are doing well and thriving except this one.  Any suggestions?  They get flakes in the morning and flakes plus bloodworms in the evenings.  Thanks.
Dina

Answer
Hi Dina;

One of my balas was getting a bit thin when being fed on flakes until I switched them to a small pelleted diet and gel foods. Maybe yours needs a more dense and heavier diet too. The flakes are so thin that larger types of fish can't eat enough to keep weight on. Go easy on them though. It's easy to overfeed those types of foods.

Or, he may have something wrong internally. It could even be an intestinal parasite or something. It's nearly impossible to determine such things in fish because we can't do the same diagnostics as easily as other types of pets. It might be helpful to isolate him and treat him with a medicated food for internal parasites. It might help him get more food too and build him up a bit. Balas can be a bit territorial when there's only two of them and a weaker one sometimes can't get as much food as he needs.

Good luck...

At Your Service;
Chris Robbins